// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_PUBLIC_CHILD_REQUEST_PEER_H_
#define CONTENT_PUBLIC_CHILD_REQUEST_PEER_H_

#include <stdint.h>

#include <memory>
#include <string>

#include "content/common/content_export.h"

namespace base {
class TimeTicks;
}

namespace net {
struct RedirectInfo;
}

namespace content {

struct ResourceResponseInfo;

// This is implemented by our custom resource loader within content. The Peer
// and it's bridge should have identical lifetimes as they represent each end of
// a communication channel.
//
// These callbacks mirror net::URLRequest::Delegate and the order and
// conditions in which they will be called are identical. See url_request.h
// for more information.
class CONTENT_EXPORT RequestPeer {
public:
    // This class represents data gotten from the Browser process. Each data
    // consists of |payload|, |length|, |encoded_data_length| and
    // |encoded_body_length|. The payload is valid only when the data instance is
    // valid.
    // In order to work with Chrome resource loading IPC, it is desirable to
    // reclaim data in FIFO order in a RequestPeer in terms of performance.
    // |payload|, |length|, |encoded_data_length| and |encoded_body_length|
    // functions are thread-safe, but the data object itself must be destroyed on
    // the original thread.
    class CONTENT_EXPORT ReceivedData {
    public:
        virtual ~ReceivedData() { }
        virtual const char* payload() const = 0;
        virtual int length() const = 0;
    };

    // A ThreadSafeReceivedData can be deleted on ANY thread.
    class CONTENT_EXPORT ThreadSafeReceivedData : public ReceivedData {
    };

    // Called as upload progress is made.
    // note: only for requests with upload progress enabled.
    virtual void OnUploadProgress(uint64_t position, uint64_t size) = 0;

    // Called when a redirect occurs.  The implementation may return false to
    // suppress the redirect.  The ResourceResponseInfo provides information about
    // the redirect response and the RedirectInfo includes information about the
    // request to be made if the method returns true.
    virtual bool OnReceivedRedirect(const net::RedirectInfo& redirect_info,
        const ResourceResponseInfo& info)
        = 0;

    // Called when response headers are available (after all redirects have
    // been followed).
    virtual void OnReceivedResponse(const ResourceResponseInfo& info) = 0;

    // Called when a chunk of response data is downloaded.  This method may be
    // called multiple times or not at all if an error occurs.  This method is
    // only called if RequestInfo::download_to_file was set to true, and in
    // that case, OnReceivedData will not be called.
    // The encoded_data_length is the length of the encoded data transferred
    // over the network, which could be different from data length (e.g. for
    // gzipped content).
    virtual void OnDownloadedData(int len, int encoded_data_length) = 0;

    // Called when a chunk of response data is available. This method may
    // be called multiple times or not at all if an error occurs.
    virtual void OnReceivedData(std::unique_ptr<ReceivedData> data) = 0;

    // Called when the transfer size is updated. This method may be called
    // multiple times or not at all. The transfer size is the length of the
    // response (including both headers and the body) over the network.
    // |transfer_size_diff| is the difference from the value previously reported
    // one (including the one in OnReceivedResponse). It must be positive.
    virtual void OnTransferSizeUpdated(int transfer_size_diff) = 0;

    // Called when metadata generated by the renderer is retrieved from the
    // cache. This method may be called zero or one times.
    virtual void OnReceivedCachedMetadata(const char* data, int len) { }

    // Called when the response is complete.  This method signals completion of
    // the resource load.
    virtual void OnCompletedRequest(int error_code,
        bool was_ignored_by_handler,
        bool stale_copy_in_cache,
        const base::TimeTicks& completion_time,
        int64_t total_transfer_size,
        int64_t encoded_body_size)
        = 0;

    virtual ~RequestPeer() { }
};

} // namespace content

#endif // CONTENT_PUBLIC_CHILD_REQUEST_PEER_H_
